Distributed Monitoring System Based on Wireless Sensor Network

在超精密加工过程中,一个有效的监测系统能够保持加工刀具处于最佳的加工条件,延长刀具寿命,提高零件加工质量。该文提出一种基于无线传感器网络的分布式监测系统,实现了多机床的实时监测。实验结果显示了该系统的有效性。In ultra-precision machining processes,an effective monitoring system can keep machine tools in the best condition and delay the occurrence of tool wear and improve the quality of workpieces.In this paper,a distributed system is developed for monitoring of multi-machine based on wireless sensor network.The experimental results have shown the effectiveness of the proposed distributed system.福建省科技重大专项/专题资助项目(2006HZ0002-4);福建省科技计划重点项目(2008H0012);863计划重点项目(2008AA042501

Accounts receivable LTV ratio optimization based on supply chain credit

基于供应商、核心企业和银行三方合作的供应链框架,假定供应商和核心企业的违约率外生,提出供应链信用度的定义,建立并分析银行贷款价值比的决策模型.研究表明,供应链应收账款融资的银行存在最优贷款价值比,且最优贷款价值比高于供应商单独融资的贷款价值比;一定条件下,银行最优贷款价值比与供应链的信用度、核心企业影响度、产品销售价呈正相关;与应收账款额度、产品批发价、银行风险厌恶程度呈负相关.所得结果有助于银行融资择向及确定应收账款最优贷款价值比.Assuming that the supplier and the core enterprise's default rate is exogenous,we define supply chain credit on the basis of the framework of supply chain comprised of the supplier,the core enterprise,and the bank.The decision model on bank loan to value( LTV) ratio is developed and analyzed.It is shown that the optimal LTV ratio exists,and the optimal LTV ratio based on the supply chain is higher than that for the supplier financing alone.At certain conditions,the bank's optimal LTV is positively correlated to supply chain credit,the effect of the core enterprise and the product sale price,while it is negatively correlated to accounts receivable amount,product wholesale price and the degree of risk aversion of the bank.The numerical simulation results will be helpful for banks to choose financing direction and account receivable optimal LTV ratio.国家自然科学基金资助项目(10YJC630320); 广东省道路运输管理局资助项目~

ON-LINE IDENTIFICATION of WHEEL WEAR CONDITION IN PRECISION GRINDING BASED ON INFORMATION FUSION

高质量非球面光学元件批量制造是目前精密磨削技术力求实现的目标。为了提高非球面光学元件精密磨削的加工效率,必须在加工过程中动态识别砂轮磨损状态,在砂轮接近或达到寿命周期时对其进行修整。寻求一种经济可行的方式,实现砂轮寿命周期在线评估,利用声发射、砂轮振动、磨削力等多种类型加工过程信号,提取和选择能够全面、灵敏反应砂轮磨损状态的特征,基于dEMPSTEr-SHAfEr证据理论,进行多源信息融合,实现精密磨削砂轮磨损状态在线识别。Grinding wheel should be addressed when it just reaches its expectancy in order to achieve high machining efficiency of aspheric optical lens.The realization of on-line estimating wheel life is based on the automatic identification of the wheel wear condition.Characters of dynamical process signals change accompanied with the lapse of the wheel life.Therefore,process signals can be used to monitor and estimate the wheel condition.Acoustic emission(AE),wheel vibration and grinding force are picked up to abstract three kinds of representative monitoring parameters.They are the skewness of the AE power spectrum,the complexity degree of the wheel vibration and the ratio of normal component and tangential component of the grinding force.These monitoring parameters are sensitive to different macro- and micro- wear of grinding wheel.The DempsterShafer evidence theory,which is one of the decision-level information fusion technologies,is employed to acquire a reliable decision about the status of the grinding wheel.福建省自然科学基金计划资助项目(2012J05098)~

Study on Method and Compensation Technology of off-axis Wedge Aspheric Parallel Grinding

针对精密光学系统中对高精度离轴楔形非球面透镜的加工要求,提出采用由倾角可调三轴摆动式数控夹具系统和精密磨床数控系统(COMPuTEr nuMErICAl COnTrOl,CnC)协调完成离轴楔形非球面透镜的高效加工方法。设计三轴摆动式数控夹具机构及控制系统相关程序,完成夹具制造及调整,在数控精密平面磨床上实现对离轴楔形非球面平行磨削加工。倾角可调夹具的设计简化原有的加工工序,提高加工效率。根据平行磨削加工原理对加工插补误差和工件形面误差进行模拟计算,结果表明:夹具旋转误差以及工件的形状尺寸会对加工精度产生较大影响。根据模拟结果和平行磨削方法原理,设计工件加工误差的在位补偿方法。通过平行磨削加工及补偿试验证明:在位补偿方法可以有效提高工件的加工精度。To satisfy the machining requirement of high-precision off-axis wedge aspheric lens in precision optical system,a grinding method of off-axis wedge aspheric with high efficiency using the coordination of the 3-axis computer numerical control(CNC) clamp and high-precision CNC grinding system is presented.The structure of 3-axis rotation CNC clamp and the control software are designed and achieved.The parallel grinding method of off-axis wedge aspheric lens is realized in the CNC plane grinding machine by using the proposed clamp.It simplifies the grinding process and improves machining efficiency.The interpolation error and machining profile error are simulated according to the principle of parallel grinding.The simulation results show that the rotation errors of clamp and the workpiece's sharp have an effect on the machining accuracy remarkably.Based on the simulation results and the principle of parallel grinding,the onsite compensation method is implemented.The machining and compensation experimental results show that the machining accuracy can be improved effectively through compensation method.国家高技术研究发展计划(863计划;2008AA042501);福建省科技重大专项/专题(2006HZ0002-4)资助项

Effect of Ni~(2+) and Sn~(2+) Modified SO_4~(2-)/ZrO_2 Solid Super-Acid Catalysts on Visbreaking of Heavy Petroleum Oil

稠油黏度高的特性使其开采难度较大。为降低胜利油田稠油的黏度,制备了金属离子(Ni2+和Sn2+)改性的SO42-/ZrO2固体超强酸催化剂,考察了这两种催化剂对稠油的降黏性能。实验结果表明,Ni2+和Sn2+改性的SO24-/ZrO2固体超强酸催化剂能在较低的温度下催化稠油降黏,在反应温度240℃、压力3~4MPa、反应时间24h、稠油与催化剂质量比100∶0.05的条件下,稠油的黏度由0.319Pa.s分别降至0.135Pa.s和0.163Pa.s,降黏率达57.7%和48.9%。反应后,稠油中的饱和烃含量增加,芳烃、胶质和沥青质含量减少,杂原子S和N的含量降低。同时发现,水的存在对稠油降黏不利。SO2-4/ZrO2 solid super-acid catalysts(SZ) separately doped with Ni2+ and Sn2+(Ni2+/SZ,Sn2+/SZ) were prepared for catalytic visbreaking of heavy petroleum oil from Shengli oil field.The visbreaking reactions were carried out under conditions of 240 ℃,3-4 MPa,mass ratio of heavy petroleum oil to catalyst 100 ∶0.05 and reaction time 24 h.The effect of water content on viscosity change of heavy petroleum oil was also investigated.Both the catalysts can promote thermolysis of heavy petroleum oil,and make the viscosity dropping from 0.319 Pa·s to 0.135 Pa·s(Ni2+/SZ) and 0.163 Pa·s(Sn2+/SZ),respectively.The visbreaking rates are 57.7% and 48.9% correspondingly.After reactions,content of saturated hydrocarbons increases and contents of aromatics,resin and asphaltene decrease.At the same time,sulfur and nitrogen contents in heavy petroleum oil also reduce.The presence of water is disadvantageous to visbreaking of heavy petroleum oil.国家"973"计划项目(2004CB217805

The vibration and temperature wireless monitoring system research for the ultra-precision grinding machine

开发了一套基于无线传输理论的精密磨床振动和温度无线监测系统,传感器和红外测温仪采集到的振动和温度信号接入相关的调理电路,经无线传输设备以一定的格式发送至远端的控制PC上。在状态监测控制端,基于VISuAl bASIC6.0开发的在线监测软件,显示振动信号幅域、频域处理结果以及温度信号的最高温度值和温度值曲线,以此判断机床是否处于正常工作状态。Based on the wireless transmission,this paper developed a set of vibration and temperature monitoring system.The vibration and temperature signal collected by the sensors and infrared radiation thermometer was sent to wireless transmission equipment after processed by the adjustment circuit,then sent to the distant control computer in some format.At the condition monitoring control terminals,the analysis results of the vibration and temperature signal was shown using the monitoring software based on the Visual Basic 6.0.The vibration signal was analyzed from the amplitude domain and frequency domain.The highest temperature and temperature curve was shown.As a result,we can judge whether the machine was in normal working condition.国家自然科学基金项目(No.51075343);福建省自然基金项目(No.2010505122

利用数字出版技术促进学术期刊发展 ——以“中文期刊外文版数字出版工程”JTP数据库为例

文章以中国知网的&ldquo;中文学术期刊外文版数字出版工程&rdquo;为例介绍了如何利用数字出版技术提高学术期刊质量的一些新方法、新措施，以及如何利用先进的数字出版技术，有效开拓期刊出版形式，提升期刊的内容质量和出版质量，并扩大期刊的学术影响力及社会影响力，促进学术期刊的发展。</p

Effect of Organic Nickel Catalysts on Visbreaking of Heavy Oil

利用自制的油酸镍和镍联吡啶铬合物有机镍均相催化剂对胜利油田稠油进行降粘实验.结果表明,两种催化剂都能有效地降低稠油粘度.在240℃,2MPa条件下,使用油酸镍催化剂,当催化剂加入量为稠油质量的0.2%时,反应24h后稠油降粘率为62.7%,使用镍联吡啶催化剂,当催化剂加入量为稠油质量的0.2%,水加入量为稠油质量的10%时,反应24h后稠油降粘率达到63.0%。族组成分析发现,反应后油品中饱和烃含量增加,芳香烃、胶质和沥青质含量减少。在降粘过程中稠油的重质组分发生了催化裂解,并伴随有C-S健和C-C键断裂,生成硫化氢、甲烷、乙烷等气体。Nickel oleate catalyst and nickel 2,2'-bipyridine complex catalyst were prepared and used to reduce the viscosity of heavy oil from Shengli oilfield.Viscosity reducing ratio of heavy oil was 62.7%by using nickel oleate catalyst under the conditions of the mass ratio of nickel oleate catalyst to the heavy oil 0.2%,240℃,2 MPa and reaction time 24h.While under the same conditions, viscosity reducing ratio of heavy oil with 10%water was 63.0%by using nickel 2,2'-bipyridine complex catalyst.The composition of the heavy oil before and after cracking reaction was determined by liquid-solid adsorption chromatography.The results showed that the mass fraction of saturates increased,while that of aromatic,resin and asphaltene decreased after the visbreaking reaction.The mechanism of visbreaking reaction showed that the catalytic cracking of heavy composition in heavy oil took place,with the C-S and C-C bonds broken,and hydrogen sulfide,methane,ethane and other gases produced.国家“973”计划项目(2004CB217805